Electric-lighting system



2 Sheets-Sheet 1.

(No Model.)

- F. A. CHENEY.

ELECTRIC LIGHTING SYSTEM.

Patented Mar. 22, 1887.

u. PETERS. Hmln-Lilhngrupher, Wzxhingtvm a a (No Model.) 2 Sheets-Sheet 2. RA. CHENEY.

ELECTRIC LIGHTING SYSTEM.

No. 359,713. Patented Mar. 22, 1887 y MMGW A rromvns' N. PETERS, Pholu-hthugmphcv. Washingiou. v.6.

- UNITED STATES PATENT OFFIcE.

FREDERICK A. CHENEY, OF TROY, NEV YORK.

ELECTRIC-LIGHTING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 359,713, dated March 22, 1887,

Application filed September 28, 1886. Serial No. 214,728.

(No model.)

- ing and forming a part of the same.

This invention relates more particularly to systems for operating incandescent electric lamps, and it will be herein described as applied to such systems, although it may be applied to advantage to circuits or systems for running or operating other eleetrical-translating devicessuch, for example, as semi-incandescent lamps, motors, and the like.

The most common method of running incandescent lamps heretofore practiced is that known as the multiple-arc system, in which the lamps are connected singly in derived or cross circuits between the main conductors from any given source of current. Another plan, and one more desirable in many respects, is to run two or more lamps in series in the same circuit. This may be done by connecting all the lamps directly in the same path, or, as is more usual, by either running two or more multiple groups in series with one another, or dividing the circuit into two or more paths and running a given number of lamps in series in each path.

In the case of simple multiple are the nu nr ber of lamps in or out of circuit has no effect upon the others, for the reason that a constant electro-motive force is maintained in the circuit, either by the generator itself or by means of a suitable regulator acting upon it; but the electro-motive force must necessarily be low and the line-conductors large, in order to offer but little resistance and to carry a current of great volume or quantity and low potential. In the case where all the lamps are run in series in one circuit means must be provided for completing a path around any lamp that is extinguished, whether by accident or design, in which case the variation in resistance will not affect the candle-power of the other lamps if a regulator be used at the machine for maintaining a uniform flow of current. The number of incandescent lamps that can be practically run in this manner, however, is

comparatively small, and the general distribution of the lights is obtained only by increasing very greatly the length of the main conductors, which involves a corresponding loss or waste of electrical energy. Vhen the lamps are run in multiple series, or series multiple in the ordinary way, these objections are very largely obviated; but it is neeessary to maintain in either case the same resistance in each branch of the circuit, as other wise some branches will'receive more than their due proportion of current, hence it is necessary to, insert an equivalent resistance for every lamp removed from the circuit. So

that while the plan of dividing up a given I circuit into two or more branches and running the lamps in series in the branches presents many advantages overothers, by reason of the fact that comparately small conductors and currents of high potential may be used, and that lamps may be run at greater distances from the machine with smaller loss of energy than by the multiple-arc system, and distributed better than if all were connected in series in one circuit, still there is no saving in the amount of current required in running this system,while it is necessary to introduce into the circuit a resistance equivalent to every lamp removed therefrom. To remedy this and in other respects to improve and render practicable the system of running a large number of incandescent lamps in series is the object of my present invention.

In Garrying out the invention I divide the circuit from a given generator into, say, two branches. In each branch Iplace two or more incandescent lamps, the number or character of the lamps, whenever practicable,being such that the aggregate resistance of the lamps in each branch shall average about the same. I then place in each branch or division of the circuit a variable resistance, and provide a means for cutting in or out portions of these resistances in such manner that a resistance equal to the difference of resistance between the two branches will always be included in that branch which has the fewer lamps, or from which the greater number of lamps have been removed. In other words, in place of substituting for each lamp extinguished a corre sponding resistance, I balance or equalize the resistance of the two branches, so. that if a certain number of lamps be turned off in each branch it is only necessary to increase the resistance of the branch with the smaller number of active lamps until it equals that of the other, which may be very much less than it would be were all its lamps in circuit.

What is true of two branches is obviously true of any number-that is to say, a circuit may be split up into any number of paths and a given number of lamps inserted in each path. A rheostat is also connected with each branch, and these latter are varied in such manner as to balance the resistances of the several branches, compensating for lamps removed, so that the resistance of every branch shall be equal to that having the greatest num ber of active lamps, or, in other words, the maximum resistance.

Various forms of apparatus for balancing and equalizing the several branches of a system of this kind may be employed,and in illustration of the principle of the invention, and of the manner in which the same is or may be carried into effect, I have shown a special form of mechanism devised by me for use in a circuit divided into pairs of branches, and in which one branch of a pair is balanced with the other and one pair of branches with another pair. In this case it is obviously desirable that the number of pairs should be two, four, eight, and so on.

I have also shown another form of apparatus, invented by Joseph A. Powers, which is adapted for use with an arbitrary number of branches.

Having thus described the method and briefly out-lined the character of the apparatus which comprise my invention, I shall now describe the same in detail by reference to the accompanying drawings.

Figure 1 is a diagram illustrating the system. Fig. 2 is a view in elevation of an automatic apparatus for balancing and equalizing two branches of a circuit. Fig. 3 is an under plan view of the contact-plates used in the said appartus. Fig. at is a side view of Fig. 2with the resistance-coils and contactplates omitted. Fig. 5 is a diagram of the system with a modified form of automatic regulator used therein.

LetA designate any suitable form of d ynamomachine provided with a regulator, 13, that is capable of maintaining a uniform flow of current through the circuit.

C O are the main conductors of the circuit from the machine. At any given point the conductor 0 is branched, for' example, into four subdivisions, 8, 4, 5, and 6. In these branches given numbers of incandescent lamps D are inserted in series. The several branches are brought together again near the generator, or at any other convenient point, in the manner shownthat is to say, 3 and 4 are united to a common conductor, 1, and 5 and 6 are joined in a conductor, 2. The conductors 1 and 2 in like manner are brought together and joined to the conductor 0. Between the conductor G and the branches 1 and 2 are placed rheostats of variable resistances, and so likewise between conductors l and 2 and the branches 3 and 4 and 5 and 6, respectively, and the resistance which any rheostat is capable of interposing in the circuit should be equal to the maximum resistance of the branch with which it is to be connected, or any corresponding branch.

As between any two branch circuits, the method of regulation is to equalize or balance the resistances by introducing suflicicnt resistance in one branch to compensate for the difference between the number of lights in the two branches, the resistance being added to that branch in which the fewer lights are running.

As between any two pairs of branches, or what may betermed resultant branchesas those designated 1 and 2, forinstancethe resistances are balanced in the same way. Any change in the total resistance of the circuit, resulting from the removal or insertion of lamps, will be compensated for by the main-circuit regulator and the total current maintained uniform. An automatic device for effecting this is shown, Figs. 2, 3, and 4.

M and M are the two helices having cores mm. Above the helices is pivoted a lever, A, carrying two metallic plates or arms, L. insulated from one another. These plates are provided with contact-brushes a b, which are arranged to sweep over a series of contact plates or points, 5. The latter are attached to or embedded in a piece of insulating material, S, and on opposite sides thereof, and the several plates are connected by coils It or 1%, each of a definite resistance equal to orless than that of one of the lamps. One contact'plate on each side of the strip or sectors, and at op posite ends of the same, covers a little more than one-half the length of the strip. The cores m m are loosely suspended from the ends of the lever A, so that a PIGIlOlldGI'ZtHCG in magnetic attraction in one coil tilts the lever A and causes the brushes a I) to sweep over toward the corresponding end of the series of plates S.

This invention is adapted for use with two branches of a circuit, and when in action one coil is included in each branch. The wires after leaving the coils are connected with the arms L, respectively, and the ends of the branches containing the lamps are connected to the long plates above described.

Normally, or when the same number of lights is burning in each branch, the arms L assume a vertical position, and the brushes a I) rest upon the long contact-plates, so that no resistance is interposed by the apparatus in either circuit. If lights be now cut out from one branchfor example, that including the coil M--the increasd ilow of current therein draws down the lever A toward the coil M, until by such movement a resistance is added to the branch that re-establ ishes an equilibrium of resistance and current between the two branches. If a certain number of lamps be then ICC , ing the least resistance.

removed from the other branch, the coil M acquires a corresponding additional power, so' that the lever A is drawn in an opposite direction until the resistances and currents are again equalized.

It isof course desirable that each lamp of a series be provided with an automatic as well as a manual switch, both of which should be capable of completing a shunt of low resistance around a lamp when extinguished; but as such devices are now well understood I shall not describe them in detail.

I shall now indicate the character of the apparatus, which is adapted for use with an arbitrary number of branches which are to be balanced one against another. Referring to Fig. 5, the branches are represented by 15, 16, 17, and 18. In each branch is a rheostat, II, having two independently-movable contactarms, I and J. The branches are severed and connected with these arms, so that the amount of resistance included in a branch by means of the rheostat is determined by the relative p ositions or angles at which these arms are set, as the arms are insulated from one another. The greatest resistance which any rheostat is ,capable of introducing should be equal to that of the branch having the highest resistance due to the lamps therein. The arms I are moved by some independent mechanism which is controlled by the electro-magnets I in the branches. As an illustration of this I have shown a Weston regulating mechanism as applied to one of the rheostats. This apparatus is fully described in United States Patent No. 316,089, dated April 21, 1885. The other arms, J, are all connected to a rigid bar, J, and they may either be shifted by hand or have a tendency to move in a direction opposite to that of the hands of a clock, so that one arm J will always be in contact with one arm I, the latter being that attached to the rheostat offer- This determines the position of all the other arms J, and is the standard with which the resistances of the other circuits are balanced. For example, assume that more or less lamps are shunted out of all the branches, except that numbered 16 in Fig. 5. The arms I of such branches will be moved to positions on their respective rheostats, where they insert just sufficient resistance to balance all the branches. None of the arms J will move, however, because there has been no change in the resistance of branch 16, and thearm J of that branch is prevented from moving by its accompanying arm I. The resistance of each branch will therefore be adjusted to correspond with the resistance of branch 16. But now assume that one or more lamps are turned off from branch 16. The resistance of this branch being thereby lowered, the arm I of its rheostat is shifted to the left. It is of course followed by the arm J, which is impelled to the left by its coiled spring. The movement of the said arm J causes a corresponding movement of all the other arms designated J, so that equal parts of resistance are simultaneously removed from all the branches. The regulator at the machine rcsponding to this reduction of resistance reduces the current correspondingly, keeping itZat normal, so that there is,or should be, no movement of any of the arms I, except that in circuit 16.

Should the number of lamps removed, as above stated, from branch 16 be so small as not to reduce the resistance of said branch below that-0f any of the others, its two arms will stop as soon as the normal current flows through its regulating-magnet, and this fixes the standard by which all the other resistances are adjusted. On the other hand, should the number of lamps removed from 16 be sufficient to reduce its resistance below that of one of the other branches, its two arms will move until the arm J of that branch which has the highest resistance stops and arrests the movement of all the other arms J. The arm I of branch 16 will then proceed alone until it has inserted a resistance in 16 sufficient to bring its total resistance up to the new standard.

I am aware that it is not new to regulate groups of incandescent lamps in multiple arc with each other in circuits from the main conductors to an intermediate conductor by va rying the resistance between said intermediate conductor and the mains to compensate for lamps eutin or out, and this I do not claim; but

\Vhat I claim is- 1. The method herein described of regulating an electrical distributing system, which consists in running the working devices in series, in branches, or divisions of the circuit, varying the resistance ofthe branches to compensate for working devices removed or inserted, and equalizing the resistance of all the branches with that having the greatest nun1- ber of working devices or the highest resist ance, and at the same time varying or regulating the electro-motive force of the current, so as to maintain a uniform current in the circuit, as herein set forth.

2. The method herein described of regulat ing an electrical distributing system, which consists in dividingacircuitinto two, four, or eight pairs of branches and running the working devices in series in said branches, balancing the resistance ofthe branches of each pair, when translating devices are cut in or out of circuit, by adding to the resistance of that branch which has the lower resistance until its resistance equals that of the other, balancing each pair of branches ina similar manner, and regulating the production of current so as to maintain a uniform current in the circuit,

stats, and equalizing the resistances of the branches with that of the branch containing the greatest number of Working devices, or the highest resistance, as set forth.

4.. The combination of agenerator and regulator for producing a uniform current, a circuit divided into branches, workingdevices included in series in the branches, an electromagnet and rheostat included in each branch, and means controlled by the magnets and operating, when working devices are withdrawn from or inserted in the circuit, to adjust the rheostats and thereby equalize the resistances of the branches with that having the highest resistance, as set forth.

5. The combination, with an electric circuit divided into branches, of incandescent lamps in series in the branches, 9. rheostat and an electro-magnet in each branch, and contactarms secured to an armature-lever common to both magnets and shifted by the preponderance of attraction of one magnet over the other, whereby the resistance of the branches is balanced and maintained equal to that of the branch containing the greater number oflamps in circuit, as set forth.

6. The combination, with an electric circuit divided into working branches joined in pairs, and the resultant branches joined in pairs, of incandescent lamps in series in the working branches, a rheostat and electro-magnet in each branch, and means for varying or adjusting said rheostats, operated or controlled by the preponderance of attractive force in one magnet in a pair over the other, as herein set U 

